Tokyo Tribunal and the War Crimes of Unit 731

by Maggie Murray

​The Tokyo Tribunal (1946 -1948) found 28 Japanese military officers guilty of committing war crimes. While the Tokyo Tribunal is regarded as having prosecuted the most egregious cases, subsequent trials across the United States and other countries worldwide implicated more than 5,000 Japanese war criminals.[1] However, in 1958, all imprisoned Japanese war criminals were released.[2] Not only were most sentences left uncompleted, but the United States covered up certain atrocities, and those involved never faced trial. 

Major Japanese Military leaders were the focus of the Tokyo Tribunal. They were prosecuted for multiple atrocities committed during the war, including crimes against prisoners of war, mass killings, and attacking neutral powers. However, the Tokyo Tribunal ignored Japanese human experimentation and the biological warfare resulting from Unit 731. 


Ishii Shiro was the formal leader of experiments done in Unit 731. In the mid-1920s, Ishii became interested in biological warfare [3] and petitioned for the use of biological warfare by the Japanese military. Although not initially receptive to his ideas, a change of leadership in the 1930s led to the military backing Ishii's biological experiments conducted in Manchuria [4]. It needs to be made clear when Ishii's human experiments began, with some citing as early as 1932.[5] However, with the creation of the 'Water Purification Bureau' (1936) - a cover for the buildings housing the human experiments - experiments were being conducted routinely on a massive scale. [6]


The human experiments included vivisections, testing of chemical weapons, and amputations, among various other gruesome acts. The majority of victims were Chinese, but also included Koreans, Russians, and prisoners of war from the United States and various other countries; the estimated death toll is minimally 10,000 to 12,000 victims.[7]


Ishii Shiro did not act alone. He was replaced as commander by Masaji Kitano in 1942, and thousands of other doctors, military personnel, and nurses helped experiments take place. Following investigations into Unit 731 conducted by the United States (1945-1948) [8], Ishii and the other experimenters were offered immunity in exchange for the results of their experiments.[9] Having escaped indictment in the Tokyo trials, Ishii and other scientists continued on to have successful careers in medicine. Notably, Masaji Kitano was the founder of Japan's first commercial blood bank, known as the 'Green Cross.' There are fewer verifiable details on Ishii Shiro's post-war life, yet Russian sources recorded him to have continued working on Biological Warfare until he died of laryngeal cancer in 1959 [10]. 


Individuals involved in Unit 731 were not the only ones who escaped being prosecuted as war criminals; Emperor Hirohito - who likely knew about Unit 731 experiments, though it is not clear to what extent - was not tried at the Tokyo Tribunal, and it has been argued that this decision combined with limited press coverage distorted the public's perception of Japan's participation in war crimes. [11]


While many escaped prosecution, numerous Japanese war criminals were still prosecuted, imprisoned, and executed in the United States, China, Russia, and elsewhere. The decision to release all Japanese war criminals came at a period of great political importance for both China and the United States. As fears of Communism and the Cold War grew, the United States released Japanese war criminals, hoping to form a closer friendship with Japan. Concurrently, the Chinese Communist Party supported amnesty for Japanese war criminals to demonstrate their benevolence and success of re-education programs. [12]


The lack of repercussions faced by those involved in Unit 731 and subsequent success reflects a greater question about how wartime accountability is evaluated and who receives justice. The United States determined that the potential advance in national security from data from Unit 731 outweighed their desire to prosecute wartime atrocities and seek justice for its victims. Ultimately, the stories of many victims would remain untold and unacknowledged for decades. 




[1] Kirsten Burton, "War Crimes on Trial: The Nuremberg and Tokyo Trials," The National WWII Museum, New Orleans. November 24, 2020. 
[2] Sandra Wilson, "War Criminals in the Post-war World: The Case of Kato Tetsutaro," War in History, no. 1 (2015) 89. 
[3] Harris Sheldon, Factories of death: Japanese biological warfare, 1932-45, and the American cover-up. (London and New York: Routledge, 1994), 18. 
[4] Harris Sheldon, Factories of death: Japanese biological warfare, 1932-45, and the American cover-up. (London and New York: Routledge, 1994), 19-21, 23. 
[5] Harris Sheldon, Factories of death: Japanese biological warfare, 1932-45, and the American cover-up. (London and New York: Routledge, 1994), 30. 
[6] Harris Sheldon, Factories of death: Japanese biological warfare, 1932-45, and the American cover-up. (London and New York: Routledge, 1994), 34. 
[7] Brody et. al., "U.S. Responses to Japanese Wartime Inhuman Experimentation after World War II." Cambridge Quarterly of Healthcare Ethics, no. 23 (2014): 221.
[8] Harris Sheldon, Factories of death: Japanese biological warfare, 1932-45, and the American cover-up. (London and New York: Routledge, 1994), 189. 
[9] Harris Sheldon, Factories of death: Japanese biological warfare, 1932-45, and the American cover-up. (London and New York: Routledge, 1994), 207. 
[10] Harris Sheldon, Factories of death: Japanese biological warfare, 1932-45, and the American cover-up. (London and New York: Routledge, 1994), 230. 
[11] Kirsten Burton, "War Crimes on Trial: The Nuremberg and Tokyo Trials," The National WWII Museum, New Orleans. November 24, 2020. ​

[12] Barak Kushner,. "The Real Manchurian Candidates: Chinese war criminals in the postwar, prisoners of history." International Journal of Asian Studies, no. 20 (2023) 26-28






Bibliography

Brody, Leonard, Nie, and Weindling. "U.S. Responses to Japanese Wartime Inhuman Experimentation after World War II." Cambridge Quarterly of Healthcare Ethics, no. 23 (2014): 220-230.

Wilson, Sandra. "War Criminals in the Post-war World: The Case of Kato Tetsutaro." War in History, no. 1 (2015) 87-110. 
Nie, Jing-Bao. "Japanese doctors' experimentation in wartime China." The Lancet, December 2002. 

Kushner, Barak. "The Real Manchurian Candidates: Chinese war criminals in the postwar, prisoners of history." International Journal of Asian Studies, no. 20 (2023) 19-37. 

Sheldon, Harris. Factories of death: Japanese biological warfare, 1932-45, and the American cover-up. London and New York: Routledge, 1994. 

Fischer, Howard. "Atrocities in Asia: Japan's infamous Unit 731." Hektoen International: a Journal of Medical Humanities. Winter 2021. https://hekint.org/2021/01/07/atrocities-in-asia-japans-infamous-unit-731/#:~:text=The%20unit%20was%20a%20walled,and%20other%20 germ%20warfare%20 laboratories.

Burton, Kristen. "War Crimes on Trial: The Nuremberg and Tokyo Trials." The National WWII Museum, New Orleans. November 24, 2020. 

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